From 51c623b0de11df2d0a23f15d7484d4f940ed6142 Mon Sep 17 00:00:00 2001 From: Lirong Yuan Date: Fri, 8 Jan 2021 22:42:42 +0000 Subject: gdbstub: add support to Xfer:auxv:read: packet MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This allows gdb to access the target’s auxiliary vector, which can be helpful for telling system libraries important details about the hardware, operating system, and process. Signed-off-by: Lirong Yuan [AJB: minor tweaks to test case, update MAINTAINERS, restrict to Linux] Signed-off-by: Alex Bennée Reviewed-by: Richard Henderson Message-Id: <20200730193932.3654677-1-yuanzi@google.com> Message-Id: <20210108224256.2321-7-alex.bennee@linaro.org> --- gdbstub.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) (limited to 'gdbstub.c') diff --git a/gdbstub.c b/gdbstub.c index d99bc0bf2e..aeffdaf06f 100644 --- a/gdbstub.c +++ b/gdbstub.c @@ -2172,6 +2172,12 @@ static void handle_query_supported(GdbCmdContext *gdb_ctx, void *user_ctx) ";ReverseStep+;ReverseContinue+"); } +#ifdef CONFIG_USER_ONLY + if (gdbserver_state.c_cpu->opaque) { + g_string_append(gdbserver_state.str_buf, ";qXfer:auxv:read+"); + } +#endif + if (gdb_ctx->num_params && strstr(gdb_ctx->params[0].data, "multiprocess+")) { gdbserver_state.multiprocess = true; @@ -2233,6 +2239,46 @@ static void handle_query_xfer_features(GdbCmdContext *gdb_ctx, void *user_ctx) gdbserver_state.str_buf->len, true); } +#if defined(CONFIG_USER_ONLY) && defined(CONFIG_LINUX_USER) +static void handle_query_xfer_auxv(GdbCmdContext *gdb_ctx, void *user_ctx) +{ + TaskState *ts; + unsigned long offset, len, saved_auxv, auxv_len; + const char *mem; + + if (gdb_ctx->num_params < 2) { + put_packet("E22"); + return; + } + + offset = gdb_ctx->params[0].val_ul; + len = gdb_ctx->params[1].val_ul; + ts = gdbserver_state.c_cpu->opaque; + saved_auxv = ts->info->saved_auxv; + auxv_len = ts->info->auxv_len; + mem = (const char *)(saved_auxv + offset); + if (offset > auxv_len) { + put_packet("E00"); + return; + } + + if (len > (MAX_PACKET_LENGTH - 5) / 2) { + len = (MAX_PACKET_LENGTH - 5) / 2; + } + + if (len < auxv_len - offset) { + g_string_assign(gdbserver_state.str_buf, "m"); + memtox(gdbserver_state.str_buf, mem, len); + } else { + g_string_assign(gdbserver_state.str_buf, "l"); + memtox(gdbserver_state.str_buf, mem, auxv_len - offset); + } + + put_packet_binary(gdbserver_state.str_buf->str, + gdbserver_state.str_buf->len, true); +} +#endif + static void handle_query_attached(GdbCmdContext *gdb_ctx, void *user_ctx) { put_packet(GDB_ATTACHED); @@ -2338,6 +2384,14 @@ static GdbCmdParseEntry gdb_gen_query_table[] = { .cmd_startswith = 1, .schema = "s:l,l0" }, +#if defined(CONFIG_USER_ONLY) && defined(CONFIG_LINUX_USER) + { + .handler = handle_query_xfer_auxv, + .cmd = "Xfer:auxv:read::", + .cmd_startswith = 1, + .schema = "l,l0" + }, +#endif { .handler = handle_query_attached, .cmd = "Attached:", -- cgit v1.2.3